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Diffstat (limited to 'arch/arm/mach-qcom/scm.c')
-rw-r--r--arch/arm/mach-qcom/scm.c85
1 files changed, 56 insertions, 29 deletions
diff --git a/arch/arm/mach-qcom/scm.c b/arch/arm/mach-qcom/scm.c
index c536fd6bf827..1d9cf18c7091 100644
--- a/arch/arm/mach-qcom/scm.c
+++ b/arch/arm/mach-qcom/scm.c
@@ -22,13 +22,11 @@
#include <linux/errno.h>
#include <linux/err.h>
+#include <asm/outercache.h>
#include <asm/cacheflush.h>
#include "scm.h"
-/* Cache line size for msm8x60 */
-#define CACHELINESIZE 32
-
#define SCM_ENOMEM -5
#define SCM_EOPNOTSUPP -4
#define SCM_EINVAL_ADDR -3
@@ -63,11 +61,11 @@ static DEFINE_MUTEX(scm_lock);
* to access the buffers in a safe manner.
*/
struct scm_command {
- u32 len;
- u32 buf_offset;
- u32 resp_hdr_offset;
- u32 id;
- u32 buf[0];
+ __le32 len;
+ __le32 buf_offset;
+ __le32 resp_hdr_offset;
+ __le32 id;
+ __le32 buf[0];
};
/**
@@ -77,9 +75,9 @@ struct scm_command {
* @is_complete: indicates if the command has finished processing
*/
struct scm_response {
- u32 len;
- u32 buf_offset;
- u32 is_complete;
+ __le32 len;
+ __le32 buf_offset;
+ __le32 is_complete;
};
/**
@@ -97,12 +95,14 @@ static struct scm_command *alloc_scm_command(size_t cmd_size, size_t resp_size)
struct scm_command *cmd;
size_t len = sizeof(*cmd) + sizeof(struct scm_response) + cmd_size +
resp_size;
+ u32 offset;
cmd = kzalloc(PAGE_ALIGN(len), GFP_KERNEL);
if (cmd) {
- cmd->len = len;
- cmd->buf_offset = offsetof(struct scm_command, buf);
- cmd->resp_hdr_offset = cmd->buf_offset + cmd_size;
+ cmd->len = cpu_to_le32(len);
+ offset = offsetof(struct scm_command, buf);
+ cmd->buf_offset = cpu_to_le32(offset);
+ cmd->resp_hdr_offset = cpu_to_le32(offset + cmd_size);
}
return cmd;
}
@@ -127,7 +127,7 @@ static inline void free_scm_command(struct scm_command *cmd)
static inline struct scm_response *scm_command_to_response(
const struct scm_command *cmd)
{
- return (void *)cmd + cmd->resp_hdr_offset;
+ return (void *)cmd + le32_to_cpu(cmd->resp_hdr_offset);
}
/**
@@ -149,11 +149,12 @@ static inline void *scm_get_command_buffer(const struct scm_command *cmd)
*/
static inline void *scm_get_response_buffer(const struct scm_response *rsp)
{
- return (void *)rsp + rsp->buf_offset;
+ return (void *)rsp + le32_to_cpu(rsp->buf_offset);
}
static int scm_remap_error(int err)
{
+ pr_err("scm_call failed with error code %d\n", err);
switch (err) {
case SCM_ERROR:
return -EIO;
@@ -198,11 +199,12 @@ static int __scm_call(const struct scm_command *cmd)
u32 cmd_addr = virt_to_phys(cmd);
/*
- * Flush the entire cache here so callers don't have to remember
- * to flush the cache when passing physical addresses to the secure
- * side in the buffer.
+ * Flush the command buffer so that the secure world sees
+ * the correct data.
*/
- flush_cache_all();
+ __cpuc_flush_dcache_area((void *)cmd, cmd->len);
+ outer_flush_range(cmd_addr, cmd_addr + cmd->len);
+
ret = smc(cmd_addr);
if (ret < 0)
ret = scm_remap_error(ret);
@@ -210,6 +212,25 @@ static int __scm_call(const struct scm_command *cmd)
return ret;
}
+static void scm_inv_range(unsigned long start, unsigned long end)
+{
+ u32 cacheline_size, ctr;
+
+ asm volatile("mrc p15, 0, %0, c0, c0, 1" : "=r" (ctr));
+ cacheline_size = 4 << ((ctr >> 16) & 0xf);
+
+ start = round_down(start, cacheline_size);
+ end = round_up(end, cacheline_size);
+ outer_inv_range(start, end);
+ while (start < end) {
+ asm ("mcr p15, 0, %0, c7, c6, 1" : : "r" (start)
+ : "memory");
+ start += cacheline_size;
+ }
+ dsb();
+ isb();
+}
+
/**
* scm_call() - Send an SCM command
* @svc_id: service identifier
@@ -220,6 +241,13 @@ static int __scm_call(const struct scm_command *cmd)
* @resp_len: length of the response buffer
*
* Sends a command to the SCM and waits for the command to finish processing.
+ *
+ * A note on cache maintenance:
+ * Note that any buffers that are expected to be accessed by the secure world
+ * must be flushed before invoking scm_call and invalidated in the cache
+ * immediately after scm_call returns. Cache maintenance on the command and
+ * response buffers is taken care of by scm_call; however, callers are
+ * responsible for any other cached buffers passed over to the secure world.
*/
int scm_call(u32 svc_id, u32 cmd_id, const void *cmd_buf, size_t cmd_len,
void *resp_buf, size_t resp_len)
@@ -227,12 +255,13 @@ int scm_call(u32 svc_id, u32 cmd_id, const void *cmd_buf, size_t cmd_len,
int ret;
struct scm_command *cmd;
struct scm_response *rsp;
+ unsigned long start, end;
cmd = alloc_scm_command(cmd_len, resp_len);
if (!cmd)
return -ENOMEM;
- cmd->id = (svc_id << 10) | cmd_id;
+ cmd->id = cpu_to_le32((svc_id << 10) | cmd_id);
if (cmd_buf)
memcpy(scm_get_command_buffer(cmd), cmd_buf, cmd_len);
@@ -243,17 +272,15 @@ int scm_call(u32 svc_id, u32 cmd_id, const void *cmd_buf, size_t cmd_len,
goto out;
rsp = scm_command_to_response(cmd);
+ start = (unsigned long)rsp;
+
do {
- u32 start = (u32)rsp;
- u32 end = (u32)scm_get_response_buffer(rsp) + resp_len;
- start &= ~(CACHELINESIZE - 1);
- while (start < end) {
- asm ("mcr p15, 0, %0, c7, c6, 1" : : "r" (start)
- : "memory");
- start += CACHELINESIZE;
- }
+ scm_inv_range(start, start + sizeof(*rsp));
} while (!rsp->is_complete);
+ end = (unsigned long)scm_get_response_buffer(rsp) + resp_len;
+ scm_inv_range(start, end);
+
if (resp_buf)
memcpy(resp_buf, scm_get_response_buffer(rsp), resp_len);
out: